1. Field of the Invention
This invention relates to the field of biological testing a bacterial suspension against a variety of reagents simultaneously. More particularly the invention relates to the field of test apparatus which contains a plurality of chambers for conducting different tests upon a common test specimen.
2. Description of the Prior Art
In the past a variety of different methods has been employed for the identification of organisms in families of bacteria such as Neisseria and Enterobacteriaceae. Many of these methods have relied upon the different patterns of development of cultures in the presence of a variety of fermentation media. One of the most common species of Neisseria is N. gonorrhoeae.
Until recent years the identification of N. gonorrheae although accurate required a 12 to 16 hour incubation period. It is now possible, however, through the use of a rapid fermentation process described by D. S. Kellogg and E. M. Turner, in an article entitled "Rapid Fermentation Confirmation of Neisseria gonorrhoeae" published in Applied Microbiology, April 1973, p. 550-552, to decrease the incubation time to about four hours. This method as in the past utilizes the different growth patterns of the organisms in the variety of fermentation media but is able to speed up the fermentation process through the use of a light buffered salt solution. The basic method of patterned growth identification, however, is relatively the same. For example, N. gonorrhoeae will ferment glucose while being completely unreactive to maltose, fructose, sucrose, lactose and mannitol. Table 1 which is taken from the Kellogg-Turner article is a complete list of the species within the Neisseria genus, which includes N. gonorrhoeae, showing their individual patterns against the six most common fermentation media used in their identification.
TABLE 1: ______________________________________ Typical Growth Fermentation Reactions of Neisseria Species Glu- Mal- Fruc- Su- Lac- Manni- Organism cose tose tose crose tose tol ______________________________________ N. gonorrhoeae + - - - - - N. meningitidis + + - - - - N. lactamicus + + - - + - N. subflava + + - - - - N. flava + + + - - - N. perflava + + + + - - N. sicca + + + + - - N. flavescens - - - - - - N. catarrhalis - - - - - - ______________________________________
W. J. Brown in his paper published in Applied Microbiology, June 1974, p. 1027-1030, developed an improved method of rapid fermentation of Neisseria gonorrhoeae based on the Kellogg-Turner method mentioned above. Brown by varying the volumes of buffer-salt solutions used by Kellogg and Turner in their testing procedure was able to reduce the time necessary to obtain positive results from approximately four to two hours.
Enterobacteriaceae is a class of bacteria found in animals wherein many of the species within a genus can be identified by its growth pattern in a variety of fermentation media. Table 2 lists the typical biochemical reactions of enterobacteriaceae against the ten most common fermentation media used in their identification.
__________________________________________________________________________ Ace- tion Ni- Mann- Dulc- Inos- Sorb- Rham- Suc- Raff- Malo- (VP) trate itol itol itol itol nose rose inose nate 1 2 3 4 5 6 7 8 9 10 __________________________________________________________________________ E. coli - + + d - .+-. + d d - Shigella - + d d - d d - d - Citrobacter - + + d - + + .+-. d d Arizona - + + - - + + - - + Salmonella - + + d d + + - - - K. pneumoniae + + + .-+. + + + + + + E. aerogenes + + + - .+-. + + + + .+-. E. cloacae + + + .-+. .+-. + + + + .+-. E. hafniae d + + - - - + - - .+-. E. Lique- faciens + + + - + + - + + - Serratia + + + - + + - + - - Proteus vulgaris - + - - - - d + - - P. mirabilis d + - - - - - + - - P. morganni - + - - - - - d - - P. rettgeri - + + - + - d d - - Providencia alcalifaciens - + d - - - - d - - Providencia stuartii - + d - + d - d - - Edwardsiella - + - - - - - - - - __________________________________________________________________________ + test result generally positive .+-. test result more often positive - test result generally negative .-+. test result more often negative d different biochemical types
Although the above-mentioned methods have resolved most of the objections as to time of incubation and accuracy of results they still require a human operator to first prepare the fermentation media and place them in a series of test tubes or containers and then individually inoculate these tubes with the bacterial suspension to be tested. This preparation process is not only time consuming, but also has the disadvantage of exposing the operator to the bacterial suspension while inoculating the tubes. In some cases such as in testing of Enterobacteriaceae there can be as many twenty tubes to be prepared and inoculated. Thus itcan be seen that the amount of handling and time required to complete the inoculation can become quite substantial. Another difficulty is that the tubes or containers must be suitable to be subjected to a water bath for accelerating the rate of reaction.
U.S. Pat. No. 3,832,532 which issued on Aug. 27, 1974, in addition to disclosing a photometric apparatus and an incubator shaker device, discloses a compartmented container for testing an inoculated broth against a variety of antibiotics. This device consists of a plurality of linear arranged curvettes attached and in communication with an end reservoir. Initially the end reservoir is filled with the broth to be tested and then, through a three step physical manipulation of the entire apparatus, the inoculated broth is delivered to the plurality of curvettes and thus contacts the individual antibiotics discs located at the bottom of the curvettes.
U.S. Pat. No. 3,876,377 which issued on Apr. 8, 1975 discloses a plurality of transparent micro-receptacles mounted on a thin support each of which is provided with a dosed quantity of determined coloured reagents. The product to be analysed is introduced into each receptacle in liquid form and the reaction or non-reaction is observed.
Unlike the present invention inoculation of the above-mentioned micro-receptacles must be done individually. Also these micro-receptacles cannot be sealed once the product to be analysed is introduced; thus heating in a water bath to speed up the fermentation process would be difficult.